Apparatuses are being developed for conducting a fuzzy reasoning and having various names such as a fuzzy controller, a fuzzy computer, and fuzzy inference operation apparatus. Most of these apparatuses execute a fuzzy reasoning in accordance with modus ponens fuzzy reasoning rules, which are so-called If, then rules.
In applications of the fuzzy reasoning system, it is quite important to appropriately establish kinds of input variables to be detected from a control object, kinds and contours of membership functions, reasoning rules, etc. These various parameters for the fuzzy reasoning are determined in many cases in consideration of experiences of experts or experienced workers, accumulation of know-how, and the like. However, even when the accumulation of the knowledge in the past is taken into consideration, problems may occur, such that some input variables and rules are not fully utilized, an optimal control cannot be accomplished because of inappropriateness of rules and membership functions, and so on. In consequence, essential matters for improvement of a fuzzy reasoning control also include observating, analyzing and evaluating roles in a fuzzy reasoning of the input variables, membership functions and rules once established and mutual relationships of a plurality of rules.
However, the research of the fuzzy reasoning applications has just been started and there has not been accomplished a satisfactory research thereof in the present situation.